Improving porous asphalt by research on the clogging process

Porous asphalt is the most effective road surface for reducing traffic noise at source, i.e. the tyre-road contact. A crucial point in using this surface course is the limited acoustic durability caused by clogging of the voids. According to German investigations the noise reducing effect is reduced by 0.5dB(A) a year on average. The mechanism of the clogging process was assessed by hydromechanics and a deep look into the structure of porous asphalt using Computer Tomography (CT) to find out how dirt is transported and deposited in the voids. An analysis of the dirt was also carried out. After understanding the mechanism of the clogging process a coating of the voids with products based on nanotechnology will be tried out in the laboratory. During this investigation the possibilities for cleaning porous asphalt were also examined. Treatment of a test section on a public highway is planned. For the covering abstract see ITRD E157233